Automatic plants for kneading, rolling, cutting, drying and packaging pasta dough comprising a rolling group for obtaining dough sheets or foils, an oven for drying dough sheets or foils provided with a conveyor suitable for carrying the dough sheets loaded therein throughout the oven, a loading unit designed to load the dough sheets or foils onto the conveyor, and an extractor or unloading group designed to unload dried dough sheets from the conveyor, have already been proposed in the state of the art. Advantageously, the conveyor comprises a chain conveyor, i.e. a conveyor provided with a pair of chains running over a respective pair of sprocket wheels, the chains being designed to support a sequence of transversally extending pan-like support elements spaced apart from one another and each hung at one end thereof to one of the chains. The conveyor extends throughout the length of the oven and is usually designed to carry out a forward and a return stroke in the oven. The pan-like support elements are so shaped as to delimit a support and receiving space for one or more dough sheets between two adjacent pan-like support elements.
Dough sheets are loaded into a respective receiving space between two successive pan-like elements at a front end of the conveyor in order to take advantage of the fact that, while the conveyor chains run around a pair of sprocket wheels, the pan-like support elements, are angularly displaced from one another, thereby “opening” outwards. Moreover, still at the front end thereof the plant comprises an extractor group designed to unload dough elements or pieces that have been moved throughout the oven along a forward and a return run, downstream of the loading unit with respect to the direction of return movement of the conveyor.
Many types of pan-like support elements have been proposed.
EP-0 381 001 discloses pan-like or support elements, each comprising two foraminated plate-like elements which are spaced apart one with respect to the other, one end thereof being connected across the chains of the conveyor, whereas the other end thereof is free, thus the plate-like elements are free to be angularly displaced one with respect to the other. The shape of each pan-like support is such as to delimit a receiving space for dough to be dried between two successive pan-like supports. According to such a solution, dough sheets or pieces of lasagna located in the receiving space between two successive pan-like supports can be subjected to a drying air flow only in a direction substantially orthogonal to the plate-like elements, i.e. to the direction of the conveyor movement.
Pan-like elements have also been proposed, which comprise each a plate element with a series of end lugs extending in a direction substantially perpendicular to the plate-like element. The lugs are so dimensioned as to prevent the dough sheets from being discharged from the space delimited by two adjacent and contiguous plate-like elements. The dough sheets, upon being loaded on the pan-like supports, often slip off, or sometimes become stuck to the lugs, thus being liable to break or be damaged, and, even worse, this prevents dried lasagnas from being downloaded by being stuck to the pan-like support. Any failure in unloading the dried material results in the drying plant being stopped, manual intervention being required to remove any stuck material and cleaning any concerned pan-like support with consequent long dead times.